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Explosion-proof centrifuges are necessary for offshore applications due to the prevailing hazardous conditions. Hazardous conditions include the presence of flammable gases, flammable fluids, or both.
An errant electrical spark could result in catastrophic damage in such environments. Therefore, offshore oil and gas platforms need centrifuges to meet stringent safety requirements.
What is an explosion-proof industrial centrifuge?
An explosion-proof industrial centrifuge is a specially modified centrifuge. Specific electrical and mechanical modifications convert an industrial centrifuge to an explosion-proof grade.
Explosion-proof refers to UL classification under Class 1 Division 1 and specific groups. For example, Class 1 Div 1 Group refers to equipment suitable for: Ignitable concentrations of flammable gases, vapors or liquids:
- can exist under normal operating conditions;
- may exist frequently because of repair or maintenance operations or leakage; or
- may exist because of equipment breakdown that simultaneously causes the equipment to become a source of release.
It is important for customers to verify their specific UL specified requirements for centrifuges. Click here to access details on UL standards for explosion-proof equipment.
For international (non-US) applications, specific international electrical standards are applicable. ATEX and IEC-Ex are the most widely used standards worldwide. Though the classifications are similar to UL standards, zone specifications are important. Components designed for UL, for example, are not suitable for ATEX approval.
Why upgrade centrifuges to meet explosion-proof standards?
Industrial centrifuge upgrade to explosion-proof standards is to ensure a safe environment. In other words, any machinery can cause heat and spark when they malfunction. This can cause a potential safety risk in the presence of flammable fluids or gases.
Upgradation of industrial centrifuges addresses this potential risk factor through proper design considerations.
Modifications to upgrade a centrifuge to explosion-proof classification.
As stated above, explosion-proof upgrade modifications fall into 2 categories. Each of these categories is briefly explained below.
Electrical modifications to meet explosion-proof standards.
All electrical components on the centrifuge should be certified to meet the classification. Also, any electrical components used on the system should meet the same certification level. For example, electric motors, sensors, enclosures, etc. should all meet the applicable specification.
The tag shown below shows a typical electrical component tab showing UL classification information.
- Drive / Motor upgrade.
- Instrumentation & sensors upgrade.
- Addition of specific sensors to enhance safety.
- An enhanced vibration monitoring system.
- Temperature monitoring system.
Remote mounted control systems.
In certain cases, it is possible to install the control system in a non-hazardous area. This allows the use of standard (non-explosion-proof) controls. The control system is wired to the centrifuge which is in a hazardous environment. The wiring needs to be suitable for hazardous location classification.
Remote mounted controls offer considerable cost and time savings.
Mechanical modifications to meet explosion-proof standards.
Industrial centrifuges have certain friction components in the transmission. These parts can cause heat in case of malfunction. Direct-drive replaces friction clutches to cut the possibility of heat generation. Spark-less clutch material is also used to the same possibility of sparking as well.
- Transmission modification to replace friction components.
- Installation of inert gas blanketing system.
- Addition of system venting system.
Explosion-proof centrifuge applications
Industrial sectors using explosion-proof centrifuges
Besides the offshore O&G sector, the following industries routinely use explosion-proof centrifuges. This is again necessary due to the hazardous nature of the products being processed.
- Hemp Production
- Chemical Plants
- Biodiesel Production
Specific applications where Dolphin Centrifuge has supplied hazardous area industrial centrifuges.
- Diesel fuel purification on off-shore oil/gas platforms.
- Ethanol-based solvent extraction of CBD oil.
- Crude oil tank bottoms at Salt-water Disposal Sites (SWD).
- Refinery slop oil separation.
- Light crude clarification.
- Offshore mercury-contaminated distillate clarification.
- Biodiesel / Glycerin separation (with methanol vapors).
- Gear oil purification in mines
Cost considerations of explosion-proof centrifuges
Upgradation to explosion-proof or hazardous area suitability comes with associated costs. Depending on the specific area classification, the cost of explosion-proof upgrades varies.
For example, the cost to upgrade a standard disc stack centrifuge to Class 1 Div 2 level (most common) can add 30% to base system cost. Upgrading to Class 1 Div 1 classification adds upwards of 70% of the base system cost.
Contact Dolphin Centrifuge to get a feel for actual costs for your specific application.
Explosion-proof Centrifuge Specifications (Offshore Diesel Fuel Centrifuge)
The following table lists the specifications of an explosion-proof centrifuge manufactured by Dolphin Centrifuge. It was supplied to an offshore gas platform.
|Centrifuge Type||Alfa Laval MAB104 B-24-60|
|Centrifuge Application||Stored diesel fuel purification (diesel used for generators)|
|Explosion-Proof Classification||UL CLASS I DIVISION I Groups C &D.|
|Control Panel Enclosure Type||Cast Aluminum|
|Centrifuge Capacity||6 GPM on 13 cSt Diesel Fuel|
|Motor Power||1 HP|
|Other Explosion Proof Upgrades|
Explosion-proof centrifuges are not optional under certain operating conditions. Upgrading standard centrifuges requires adherence to strict relevant agency guidelines.
Dolphin Centrifuge has the experience and technical expertise to manufacture explosion-proof centrifuges.
Contact Dolphin Centrifuge to discuss your explosion-proof or hazardous area centrifuge application with one of our centrifuge experts.